Hello @Bingi Naganandu ,
As oanapl mentions here:
The report "Partition is below target replica or instance count" can happen in many situations. There is no single root cause for all cases. It may be a bug in the service code that prevents replicas from starting up, it may be a configuration error (for example, you ask for more replicas than the number of nodes in the local cluster), an environment error (like disk space).
Next steps are to check replicas health for that partition (to see if replicas are recycled frequently, in which case they crash in a loop, or if there are replicas in warning/error states - maybe replication is slow and it takes longer to build the replicas etc). You can also check the event log to see if there are any entries related to that partition from service fabric.
Additional troubleshooting resources: